When publishing and then locally pinning crate with custom manifest file name, crate cannot be found

[meowthsli]

Describe the bug
When developing multi-crate application, it is useful to have pinned local repositories of crates one's making changes to. So if crate has a manifest file with non-default name (i.e. like there https://github.com/meowthsli/light-startup), you can't pin it later, cause pins directive uses path and expects to find alire.toml over there.

To Reproduce
Steps to reproduce the behavior:

1. Create local crate with custom manifest file name.
2. Try to pin it locally
3. See error - crate can't be found.

Expected Behavior
It should be possible to pin to crate with custom crate manifest file names, because you can publish it with --manifest override, but you cannot pin it later.

alr version
alr version: 2.0.1
libalire version: 2.0.1
compilation date: 2024-03-21 11:30:41
compiled with version: 13.2.0

[meowthsli]

Maybe, it is useful to add manifest property to pin_attributes to allow custom manifest name.

Workaround for now: add fs link to custom manifest file with alire.toml name

[Fabien-Chouteau]

We already have the subdir/monorepo feature that should work here, especially when #1683 is in.

So let's not introduce a new solution to the same problem.